Steel toe, as the name suggests, has a non-corrosive protective cap at its toe. It gives protection for feet. It features leather upper, moisture repellent drilex lining, dual density outsole made of shock absorbent polyurethane and foam footbed. The Welt Construction allows constant air flow through the shoe, this keeps the shoes ventilated, durable and strong. It provides safety against electrical hazards.
I can't say it looks very fashionable. The blunt frontal part, stretched rear part and the symmetrical design give it a rather dull look. But at the same time it looks dependable. Good for working under hazardous environment.
Well it is likely to be used more as a safety footwear, so, it has to qualify the official standards (ASTM F2413-05) in the United States. This explains the added cost.
And there are few rants regarding longevity. I have seen it works great till being worn out after serving for 3+ years. Particularly the toe region is prone to damages. It depends a lot on usage conditions and proper shoe care.
I don't have it really, neither I would prefer to work in hazardous environment to try a pair of steel toe boots. I'm quite comfortable sitting before my computer and helping clueless guys in picking up the right pair.